Assessment of a Serial Cooling Concept for HTPEM Fuel Cell Systems for Aviation Applications

Kurzfassung

The thermal management subsystem is a significant mass contributor to a fuel cell system. In this paper a serial cooling concept for high temperature proton exchange membrane fuel cell systems is introduced and analysed. For a liquid cooling system, the coolant mass has a high share of the overall thermal management system mass. A cooling concept where multiple fuel cell units are put in serial from a coolant flow perspective allows for an increase in total temperature difference over the coolant and therefore significant reduction of coolant mass. As the temperature difference over each fuel cell unit is kept constant at 10 K, the different fuel cell units operate at different temperatures. This results in slightly less efficient and heavier fuel cell units. Furthermore, the increased overall temperature difference of the coolant also has an impact on the heat exchanger design. These trade-offs are evaluated for a different number of fuel cell units in serial and different design parameter combinations. The studies indicate that the proposed serial cooling concept offers significant weight savings or efficiency improvements, which can be traded against each other.